| // Copyright 2014 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "aemu/base/StringFormat.h" |
| |
| #include <stdio.h> |
| |
| namespace android { |
| namespace base { |
| |
| std::string StringFormatRaw(const char* format, ...) { |
| va_list args; |
| va_start(args, format); |
| auto result = StringFormatWithArgs(format, args); |
| va_end(args); |
| return result; |
| } |
| |
| std::string StringFormatWithArgs(const char* format, va_list args) { |
| std::string result; |
| StringAppendFormatWithArgs(&result, format, args); |
| return result; |
| } |
| |
| void StringAppendFormatRaw(std::string* string, const char* format, ...) { |
| va_list args; |
| va_start(args, format); |
| StringAppendFormatWithArgs(string, format, args); |
| va_end(args); |
| } |
| |
| void StringAppendFormatWithArgs(std::string* string, |
| const char* format, |
| va_list args) { |
| size_t cur_size = string->size(); |
| size_t extra = 0; |
| for (;;) { |
| va_list args2; |
| va_copy(args2, args); |
| int ret = vsnprintf(&(*string)[cur_size], extra, format, args2); |
| va_end(args2); |
| |
| if (ret == 0) { |
| // Nothing to do here. |
| break; |
| } |
| |
| if (ret > 0) { |
| size_t ret_sz = static_cast<size_t>(ret); |
| if (extra == 0) { |
| // First pass, resize the string and try again. |
| extra = ret_sz + 1; |
| string->resize(cur_size + extra); |
| continue; |
| } |
| if (ret_sz < extra) { |
| // Second pass or later, success! |
| string->resize(cur_size + ret_sz); |
| return; |
| } |
| } |
| |
| // NOTE: The MSVCRT.DLL implementation of snprintf() is broken and |
| // will return -1 in case of truncation. This code path is taken |
| // when this happens, or when |ret_sz| is equal or larger than |
| // |extra|. Grow the buffer to allow for more room, then try again. |
| extra += (extra >> 1) + 32; |
| string->resize(cur_size + extra); |
| } |
| } |
| |
| } // namespace base |
| } // namespace android |